In signal transmission applications, the selection of a coaxial cable for carrying the signal is usually determined according to the distance between two points to be connected, the signal frequency, the maximum bend radius required, and the connector space available in a particular transmitting and/or receiving device. The longer the coaxial cable is and the higher the signal frequency is, the larger the outside diameter of the coaxial cable needs to be to prevent excessive signal loss. Conventionally, coaxial cables that are applied in cable TV transmission, broadband data transmission, and microwave signal transmission usually have an outer diameter ranged from 0.25 to 1 inch when the transmission distance is between 50 and 1000 feet.
A coaxial connector is well-known in the technological field of coaxial cable transmission. Typically, a coaxial connector is connected to a mating interface connector, so that a coaxial cable connected to the coaxial connector can be electrically connected to various kinds of electronic devices.
The conventional connector for a coaxial cable has some disadvantages. For instance, to ensure good electric signal transmission, it is a must a braided conductive grounding sheath of the coaxial cable is in good contact with a main body of the connector. However, with the conventional coaxial connector technique, poor grounding contact might occur between different components, such as an inner sleeve and a collar, of the connector to result in interrupted signal transmission. FIG. 1A is a sectional view of an F-series connector 10, being illustrated as a representative example of the conventional connectors. The F-type connector 10 includes an outer sleeve 11, a collar 12 coaxially fitted in the outer sleeve 11, an inner sleeve 13 axially movably fitted in the collar 12, and a nut-shaped connecting ring 14 rotatably mounted around the collar 12.
As can be seen in FIG. 1B, a free end of a cable 15 can be inserted into the connector 10, such that a central conductor 16 and an insulating spacer 17 of the cable 15 are received in the inner sleeve 13 while a braided conductive grounding sheath 18 and an insulating sheath 19 of the cable 15 are located in an annular space between the outer sleeve 11 and the inner sleeve 13, allowing the cable 15 to be connected to the connector 10. When the free end of the cable 15 has been fully inserted into the connector 10, the cable 15 can be pulled with a sufficient force to compel the inner sleeve 13 to move from a first position closer to a front end of the connecting ring 14 to a second position closer to a rear end of the connecting ring 14, so that the inner sleeve 13 and the collar 12 are in effective grounding contact, and the outer sleeve 11 is tightly connected at a radially inward annular rib 111 thereof to the insulating sheath 19 of the cable 15.
However, in the event the pull applied to the cable 15 is insufficient, a space S will exist between the inner sleeve 13 and the collar 12, resulting in poor contact between the inner sleeve 13 and the collar 12. The poor contact between the inner sleeve 13 and the collar 12 will further degrade the electrical characteristic of the connector 10. It is obviously necessary to overcome such poor contact between the inner sleeve 13 and the collar 12 of the connector 10.
Therefore, it is tried by the inventor to develop a connector, which not only ensures effective connection of the connector main body to a coaxial cable, but also ensure good grounding contact between components in the connector main body over a long period of time, so as to maintain the cable and the connector in good electrical characteristic.